Efficient Tunable Mid-Wave Infrared Laser from 2µm Tm,Ho:YVO₄ Pumped Gain−Switched Cr²⁺:ZnSe Laser

An efficient mid-wave infrared gain-switched Cr²⁺:ZnSe laser pumped by a 2.058 µm Tm,Ho:YVO₄ laser is reported. As much as 3.86 W output is achieved with the pump power of 13.4 W at pulse repetition frequency of 15 kHz, corresponding to the slope efficiency of 30.9%. With a quartz birefringent filter inserted in the laser cavity and by rotating the external angle of the quartz birefringent filter, wavelength tuning range nearly from 2453 nm to 2508 nm with 5 nm linewidth (FWHM) is also obtained.